JDW Pathology Inc, South Africa and Division of Anatomical Pathology, University of Cape Town, South Africa.
Division of Anatomical Pathology, University of Cape Town, South Africa and Pathcare, South Africa.
S Afr J Surg. 2021 Mar;59(1):27a-27e.
The classification of gastrointestinal (GI) neuroendocrine neoplasms (NENs) has been updated in the WHO classification of tumours of the digestive tract. Mitotic rate and Ki-67 proliferation index are central to the histopathological grading of these tumours. Assessing these variables is not standardised in local practice. This study addresses this deficit in the South African context.
This is a retrospective audit of archival material of resection specimens of GI NENs (excluding appendix) at Groote Schuur Hospital from 2004 to 2017. We performed a mitotic count and immunohistochemistry for Ki-67 to reclassify tumours according to the 2019 WHO criteria.
Thirty-five resection specimens were examined. These represented stomach ( = 5), jejunoileum ( = 17), colon ( = 7) and rectum ( = 6). The mean age at the time of resection was 56 years (range 32-72). Twenty-one cases (60%) were women and 14 (40%) were men. The majority (24/35) of tumours were classified as grade 1 well-differentiated neuroendocrine tumours (WD NETs), 8/35 were classified as grade 2 WD NETs and 3/35 were classified as small cell poorly differentiated neuroendocrine carcinomas (PD NECs). Re-classification resulted in 7/35 (20%) changes in tumour grade (4 upgraded, 3 downgraded). In most instances (7/8), the Ki-67 proliferation index was the determining factor in assigning tumour grade.
This study has increased awareness of the recently updated WHO classification system. We conclude that an objective and systematic approach to counting of mitoses and determination of the Ki-67 proliferation index is recommended in routine practice.
胃肠道（GI）神经内分泌肿瘤（NEN）的分类已在世界卫生组织消化系统肿瘤分类中更新。有丝分裂率和 Ki-67 增殖指数是这些肿瘤组织学分级的核心。在当地实践中，评估这些变量尚未标准化。本研究在南非背景下解决了这一不足。
这是对 2004 年至 2017 年格罗特舒尔医院 GI NEN（不包括阑尾）切除标本的回顾性审核。我们进行了有丝分裂计数和 Ki-67 的免疫组化，根据 2019 年世卫组织标准重新分类肿瘤。
检查了 35 个切除标本。这些标本代表胃（= 5）、空肠回肠（= 17）、结肠（= 7）和直肠（= 6）。切除时的平均年龄为 56 岁（范围 32-72 岁）。21 例（60%）为女性，14 例（40%）为男性。大多数（24/35）肿瘤被归类为 1 级分化良好的神经内分泌肿瘤（WD NET），8/35 被归类为 2 级 WD NET，3/35 被归类为小细胞低分化神经内分泌癌（PD NEC）。重新分类导致 35 个肿瘤中有 7 个（20%）肿瘤分级发生变化（4 个升级，3 个降级）。在大多数情况下（7/8），Ki-67 增殖指数是确定肿瘤分级的决定因素。
本研究提高了对最近更新的世卫组织分类系统的认识。我们的结论是，建议在常规实践中采用客观和系统的方法来计数有丝分裂和确定 Ki-67 增殖指数。
